Camera iris blade

ABSTRACT

An iris blade with an integral exposure indicator formed from a sheet of synthetic resin having different colored areas, one color for the indicator and another color for the blade.

United States Patent Yoshiada 1 Mar. 28, 1972 54] CAMERA IRIS BLADE [56]Reierences Cited [72] Inventor: Risaburo Yoshiada, Tokyo-to, JapanUNITED STATES PATENTS [73] Assignee: Nikon Eigaklkai Kabushlki Kaisha(Japan Re 2 6 ,3 9 0 5/1968 Vess et a1 ..95/64 D Cine Equipment Mfg.Co., Ltd.), Tokyo- 2,297,262 9/1942 Tonnies to, Japan 3,099,198 7/1963Mueller [22] Filed: 11 9 3,292,517 12/1966 Eagle et a1. ..95/64 D [21]AppL 834,113 FOREIGN PATENTS OR APPLICATIONS 1,431,444 l/1966 France..352/141 [30] Foreign Application Priority Data Primary Examiner-JosephF Peters, Jr. Dec. 13, 1968 Japan ..43/91899 wm F. pinsak [52] US. Cl...95/64 R, 352/141 57 ABSTRACT [51] Int. Cl. ..G03b 9/02 53 Field ofSearch ..95/64 R, 64 D; 352/141 M blade Wlth an Integral exposuremdlcawr formed from a sheet of synthetic resin having different coloredareas, one color for the indicator and another color for the blade.

1 Claim, 3 Drawing Figures I I ,4 A

CAMERA IRIS BLADE This invention relates to an iris blade whichindicates underexposure or overexposure in a viewfinder of a camera.

Previous camera iris blades having over or underexposure indicators werecommonly made by adhesively assembling two separate parts. It is wellknown in the camera field that an adjustable iris blade is extremelysensitive to a pivotable balance. The two part assembly has adisadvantage in that it is difficult to apply a uniform amount ofadhesive to each assembly resulting in an adjustment to balance eachiris blade.

Other disadvantages of previous iris blades are due to the blades beingcommonly made of metal which have weight that creates an inertial errorand the metal requires anticorrosion treatment which is costly.

It is an object of this invention to provide a new and improved irisblade for a camera.

lt is another object of this invention to provide an iris blade madefrom a synthetic resin having an over or underexposure indicator formedintegral therewith.

It is a further object of this invention to provide an iris blade havinga body portion formed from black synthetic resin and having the integralindicator portion formed from red synthetic resin.

Further and other objects will be apparent from the description of theaccompanying drawings, in which like parts are designated by likenumerals.

In the drawings:

FIG. 1 is a schematic representation of an iris blade according to thisdisclosure as mounted for movement by a galvanometer relative to anoptical path and a viewfinder path of a camera;

FIG. 2 is a plan view showing a synthetic material sheet indicating anon-opaque area and an opaque area and showing an arrangement by whichtwo color iris blades may be formed from the sheet; and

FIG. 3 shows an alternate plan view of forming a two color iris blade.

Referring to FIG. 1, an iris blade 1 has a conventionally shaped bodyportion pivotally supported as in a camera. The body portion issubstantially opaque and preferably black in color for blocking outlight entering into a camera. The blade 1 has an indicator portion 2extending integrally from the blade 1. The indicator portion 2 is red incolor for a warning signal to be visible through a viewfinder 3. Whenthe indicator portion 2 extends into the viewfinder path, the cameraoperator is warned of over or underexposure of light for the film.

The iris blade 1 with the indicator 2 are made from the same material bya stamping process as viewed in FIG. 2. A sheet of transparent syntheticresin 4, such as Polycarbonate, is the starting raw material. The entiresheet 4 is first dyed red with an organic-chemical dye forming a redtranslucent sheet. Intermittent areas 6 along the sheet 4 are then dyedblack with an organic-chemical dye leaving strips 5 of red material forthe indicator 2. The blade body 1 and indicator portion 2 are stampedout from the sheet 4 thereby providing a two color iris blade formedfrom the same material.

In FIG. 3 an alternate method of forming the two color syntheticmaterial iris blade is shown. The circles 5 remain red for the indicator2 while the remaining sheet 4 is dyed black for the body portion of theiris blade 1.

I claim:

1. An iris blade for a camera comprising:

a body portion stamped from a sheet of non-opaque synthetic resinmaterial having a predetermined color, said body portion being treatedto be substantially opaque and a color different from said predeterminedcolor; and

an indicator portion formed integrally with said body portion from saidsheet of synthetic resin material of said predetermined color.

1. An iris blade for a camera comprising: a body portion stamped from asheet of non-opaque synthetic resin material having a predeterminedcolor, said body portion being treated to be substantially opaque and acolor different from said predetermined color; and an indicator portionformed integrally with said body portion from said sheet of syntheticresin material of said predetermined color.